Such handheld extruder welding devices are familiar devices, and are used primarily for welding plastic panels or similar objects. The known plastic welding devices consist essentially of a handheld drill serving as the drive system and a removable attachment for this drill. The extrusion screw is mounted separately behind the gear of the handheld drill. For the welding wire, a feed channel is provided that opens behind the mount of the extrusion screw into the space surrounding the feed zone of the extrusion screw.